The present invention pertains to a combine of the axial flow type in which, preferably, a pair of rotors having rasp bars thereon are mounted within a casing and are rotatable in opposite rotary directions repectively for coaction with arcuate, stationary concaves. Auger means are provided on the forward ends of said rotors for purposes of positively feeding crop material to the inlet end of the threshing compartment between said rotors and concaves. An elevator is on the forward end of said combine and extends upwardly and rearwardly from a header which cuts and consolidates the crop material and delivers it to the lower end of said elevator. The elevator moves the crop material upwardly and rearwardly to the lower portions of the auger means which feeds the material to the threshing elements in a somewhat undershot manner.
A feed plate extends upwardly and rearwardly from the upper end of the elevator to the forward end of said concaves to guide the crop material from the elevator to the auger means and the forward end of the threshing compartment. It has been found that when crop material is fed up such feed plate, there are several undesirable results, especially when the combine is harvesting certain types of crops. These undesirable results include: (1) a tendency for the crop material to slide back down the feed plate and thus tend to obstruct the upward delivery movement of oncoming material from the elevator and thereby retard the feeding function of the elevator; (2) a second undesirable result is that it has been found that there is a limited amount of threshing of the seeds, grains and kernels from the crop material when engaged by the auger means and this threshed material also tends to slide downwardly along the feed plate, whereby a certain amount of such threshed material falls upon the ground and thus is lost; (3) another undesirable result is that the grain threshed by the auger will be subject to possible damage if it is permitted to pass through to the threshing compartment, because threshed grain is unprotected in comparison to the crop material for which the threshing mechanism is designed and, therefore, particularly susceptible to damage; and (4) still another undesirable result is caused by the buildup of loose material at the transition between the feed plate and elevator causing blockage and potential back-feeding down the top of the elevator to the header under some crop conditions.
A typical example of axial flow type combine to which the present invention pertains is illustrated in U.S. Pat. No. 3,848,609, issued Nov. 19, 1974, to Mortier et al, and entitled "Axial Flow Type Harvesting Machines". In said patent, it will be seen that the elevator delivers crop material to an upwardly and forwardly extending feed plate which appears to be at an angle of at least approximately 30.degree. relative to a horizontal plane, said feed plate being below the auger means on the forward ends of the rotors. Such combine is not provided with any means to retard or restrict such downward movement of some of the crop material in a back-feeding direction or in providing means to retain grain threshed by the auger means and, therefore, it is the principal object of the present invention to provide means at least to minimize, if not eliminate such back-feeding tendency and loss of grain threshed by the auger means, as well as to facilitate release of threshed grain before it receives damaging impacts from the threshing mechanism, details of which are set forth below.